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CHAPTER 10: ANGULAR MOMENTUM - Coggle Diagram
CHAPTER 10: ANGULAR MOMENTUM
Angular Momentum: Rotation at Fixed Axis
Angular momentum:
Newton's Second Law:
When external torque is absent, angular momentum is conserved.
The total angular momentum of a rotating object remains constant if the net external torrque acting on is zero.
Angular momentum is a vector.
Vector Cross Product; Torque as a Vector
The direction of cross product is determined using
right hand rule.
Cross product can also be written in deerminan form.
PROPERTIES OF CROSS PRODUCT:
Torque can be defined as vector product:
Angular Momentum of a Particle
The angular momentum of a particle of mass
since,
therefore,
Angular Momentum and Torque for a Rigid Object
For a rigid body, its angular momentum when rotating around a particular axis is gven by:
A system that is rotationally imbalanced will not have its angular momentum and angular velocity vectors in same direction.
A torque is required to keep an unbalanced sytem rotating.
Example of rotational imbalance:
Conservation of Angular Momentum
The total angular momentum of a system remains constant if the net externaltorque acting on the systemis zero.
,
Angular Momentum and Torque for a System of Particles
The vector sum of all torques acting on a particle is equal to the time rate of change of the angular momentum of that particle.
Internal Torque
due to forces between particles within system
External Torque.
due to forces on the particles from bodies outside system.